URO-GEN1TAL SYSTEM. 459 



In fact this uro-genital sinus (beside the allantois, Fig. 

 124, A, that we shall examine further on) gives origin to 

 three protuberances or caeca on each side ; these elongate in 

 She direction of the superior portion of the germinal vesicle. 



1. The first of these protuberances, or, more properly speak- 

 ing, germs (Fig. 124, 1), itself gives rise to lateral vegeta- 

 tions, from which a penniform organ is formed ; this is the 



Wolffian body, which in foetal life is developed to a great 

 size and occupies the largest portion of the abdominal cavity. 

 At this same period it comprises elements analogous to the 

 glomeruli or corpuscles of Malpighi in the kidney, and seems 

 to possess the same functions that afterwards belong to this 

 latter organ ; in consequence of which function the Wolffiau 

 body has been called the primordial kidney (Jacobson, 

 Ratoke). But, towards the close of the first half of foetal 

 life in the female foetus, these organs become atrophied and 

 disappear, whilst, on the other hand, a portion of the male 

 genital organs is developed from them. 



2. The second protuberance or caecum elongates without 

 presenting secondary vegetations; this forms a single tube 

 known by the name of Mullerian duct or organ of Muller 

 (Fig. 124, 2). This is essentially arranged for the formation 

 of the most important portions of the female genital organs, 

 Fallopian tubes and uterus ; in man they form comparatively 

 useless rudimentary vestiges of the embryonic state, such 

 as the utriculus prostaticus (prostatic vesicle), and a small 

 appendage of the epididymis, the corpora Morgagnii, hyda- 

 tids of Morgagni. 



3. The third protuberance or ca3cum (Fig. 124, 3) presents 

 quite a number of secondary vegetations, originating and 

 radiating from the end of the tube. These secondary pro- 

 tuberances assume the form of canaliculi placed side by side, 

 interlace and finally converge in a little vascular tuft, against 

 which, as it were, their extremity abruptly terminates in a 

 caecum ; beyond this point they are not developed. Each of 

 these embraces, by its csecal extremity, a vascular tuft ; this 

 latter fills up the interior of the hollow of the cul-de-sac in 

 such a way as to be lodged in a terminal capsule. Thus are 

 formed the uriniferous tubes and the malpighian corpuscles 

 (glomeruli Malpighii), in one word, the kidney. 



Finally, beyond these three protuberances on each side, the 

 anterior extremity of the uro-genital sinus is developed, and 

 constitutes the allantoid canal (urachus) and the allantoid 

 bladder (vesicula allantoidiana, Fig. 124, 0, A), whose func- 



